Fingal’s Cave, Inner Hebrides, Scotland. "Fingal's Cave is a sea cave on the uninhabited island of Staffa, in the Inner Hebrides of Scotland, part of a National Nature Reserve owned by the National Trust for Scotland" via Wikipedia.
Secluded cave near Lagoa Algarve Portugal [Portugal is has it all. great food and wine sights natural spots (like this one) friendly people. and you can get away with your high school Spanish if you need to.
The Baatara gorge waterfall (also known as the “Cave of the Three Bridges”) in Tannourine, Lebanon. The waterfall drops 255 metres ft) into the Baatara Pothole, a cave of Jurassic limestone located on the Lebanon Mountain Trail.